Chemistry - A European Journal,
Journal Year:
2024,
Volume and Issue:
unknown
Published: July 27, 2024
Olefins
play
an
essential
role
in
synthetic
chemistry,
serving
not
only
as
important
synthons
but
also
key
functional
groups
numerous
bio-active
molecules.
Consequently,
there
has
been
considerable
interest
the
development
of
more
powerful
methods
for
olefins.
While
Wittig
reaction
stands
a
prominent
choice
olefin
synthesis
due
to
its
simplicity
and
ready
availability
raw
materials,
limitation
lies
challenge
controlling
cis-trans
selectivity,
hampering
broader
application.
In
this
study,
novel
Boron-Wittig
developed
utilizing
gem-bis(boryl)alkanes
aldehydes
starting
materials.
This
method
enables
creating
favourable
intermediates,
which
possess
less
steric
hindrance,
leading
trans-olefins
via
intramolecular
O-B
bonds
elimination.
Notably,
studies
have
validated
good
efficacy
modifying
bioactive
molecules
synthesizing
drug
with
great
trans-selectivity.
Furthermore,
mechanism
was
elucidated
based
on
intermediate
trapping
experiments,
isotope
labelling
studies,
kinetic
analyses.
Angewandte Chemie International Edition,
Journal Year:
2022,
Volume and Issue:
61(51)
Published: Nov. 4, 2022
Abstract
Strategies
on
the
construction
of
enantiomerically
pure
silicon‐stereogenic
silanes
generally
relies
desymmetrization
prochiral
and
symmetric
substrates.
However,
dynamic
kinetic
asymmetric
transformations
organosilicon
compounds
have
remained
underdeveloped
unforeseen
owing
to
a
lack
an
effective
method
for
deracemization
static
silicon
stereocenters.
Here
we
report
first
Rh‐catalyzed
intramolecular
hydrosilylation
(DyKAH)
with
“silicon‐centered”
racemic
hydrosilanes
that
enables
facile
preparation
benzosiloles
in
good
yields
excellent
enantioselectivities.
The
special
rhodium
catalyst
controlled
by
non‐diastereopure‐type
mixed
phosphine‐phosphoramidite
ligand
axial
chirality
multiple
stereocenters
can
induce
enantioselectivity
efficiently
this
novel
DyKAH
reaction.
Density
functional
theory
(DFT)
calculations
suggest
amide
moiety
chiral
plays
important
role
facilitating
S
N
2
substitution
chloride
ion
realize
inversion
center.
Chinese Journal of Chemistry,
Journal Year:
2023,
Volume and Issue:
41(22), P. 3063 - 3081
Published: June 10, 2023
Comprehensive
Summary
Hydrogermylation
of
alkenes
and
alkynes
provides
a
straightforward
synthetic
route
to
organogermanium
compounds
that
have
been
found
applications
in
organic
synthesis,
medicinal
chemistry,
material
science.
This
paper
reviews
the
advances
transition‐metal‐catalyzed
hydrogermylation
unsaturated
carbon‐carbon
bonds,
including
alkenes,
alkynes,
dienes,
allenes,
with
objective
providing
readers
status
field.
Progress,
problems,
perspectives
this
field
are
discussed.
Chemical Communications,
Journal Year:
2022,
Volume and Issue:
58(60), P. 8380 - 8383
Published: Jan. 1, 2022
A
photo-induced
transition-metal-free
regioselective
hydroborylation
of
α,β-unsaturated
carbonyl
compounds
is
developed.
The
PhSSPh
reagent
was
employed
as
the
photocatalyst,
and
NHC-BH3
used
boron
source.
This
transformation
shows
a
broad
substrate
scope
provides
wide
range
α-borylcarbonyl
molecules
in
good
to
excellent
yields.
Chemical Science,
Journal Year:
2022,
Volume and Issue:
14(5), P. 1123 - 1131
Published: Dec. 21, 2022
A
highly
enantioselective
palladium-catalyzed
hydrosilylation
of
1,3-diynes
with
dihydrosilanes
was
established
for
the
facile
preparation
Si-stereogenic
enynes
and
an
enyne-linked
chiral
polymer
(polyenyne)
in
good
yields
excellent
ees.
Organic Letters,
Journal Year:
2023,
Volume and Issue:
25(23), P. 4359 - 4365
Published: June 7, 2023
A
highly
regio-
and
stereoselective
hydrochlorination/cyclization
of
enynes
has
been
reported
by
FeCl3
catalysis.
variety
undergo
this
cyclization
transformation
with
acetic
chloride
as
the
chlorine
source
H2O
providing
protons
via
a
cationic
pathway.
This
protocol
provides
cheap,
simple,
stereospecific,
effective
to
afford
heterocyclic
alkenyl
compounds
Z
isomers
high
yields
(≤98%)
regioselectivity.
Organic Chemistry Frontiers,
Journal Year:
2022,
Volume and Issue:
9(19), P. 5225 - 5236
Published: Jan. 1, 2022
Herein
we
report
the
use
of
rongalite
in
PEG-400
as
a
general,
efficient,
and
environmentally
benign
reductive
system
for
synthesis
wide
range
2,5-disubstituted
chalcogenophenes
from
elemental
sulfur,
selenium
tellurium.
